933 4 Wire Line Isolation Unit Bridging The Gap In
Radio Communications

Designed primarily to interface the
9412AMU or 960/980AMC into a single PABX extension, the
933LIU allows for simple connection into an existing
network. It provides isolated 4-wire audio and 'Off Hook'
indication via a set of relay contacts.

The connection to the 9412AMU is
via a 6-way port, with a 1 to 1 cable between. An 8-way
port, with a flying lead cable, is used to interface to
the PABX line and another 6-way port allows for control
of the relay contacts on the PABX port.

The unit is fully approved to the
TS001 standard. This allows for any non-approved audio
equipment to be interfaced into PABX networks. It
provides isolated 600ohm balanced 4-wire audio lines and
bi-directional relay contact control lines.

Audio levels on both pairs are
limited with back to back diodes and attached equipment
is protected by low ohm series resistors and in line
'pico' fuses. Relays are enabled by applying 12 Volts DC
to the appropriate control lines.

Supplied in a small "Jiffy box"
enclosure (130x67x46mm), with mounting hardware and
interface cables provided, the 933LIU requires no setting
up and is very easy to integrate into an existing system.